Measure of tension differential



March 1, 1927.

O. SMITH MEASURE OF TENSION DIFFERENTIAL lFiled July 1. 1925 PatentedMar. l, 1927.

UNITED STATES OAKLEY SMITILOF CHICAGO, ILLINOIS.

MEASURE OF TENSION DIFFERENTIAL.

`Applix'sationled July 1, 1925. Serial No. 40,776.

My present invention relates to the provision of lan instrumentVformeasuring the differential in tension ofligamentous and otheranatomical tissue under varying but known stress or effort, that is tosay, by measuring the difference of different tissue groups to resistknown pressures data can be obtained by which the physical condition ofthe respective tissue groups can be known, and also, differences ofresistance of particular tissue groupspermit o f a localization of anyabnormality which mayy be present.

My instrument may and should be reversed in its application, that is, ifa differ ence of resistance to stress is indicated in one position theplungers should be turned about to ascertain if a like differential willbe indi` cated, thereby checking up the action ofthe tissue and theaccuracy of manipulation. Also, as will hereinafter be noted, I haveprovided separate instrumentalities showing the amount of stress exertedby the respective plungers. From the action of these instrumentalitiesin themselves a differential of resistance could be calculated, but Ihave also provided other and separate means for showing directly anydifferential which may exist. Again, by providing separate means forindicating the stress upon each plunger it is possible to vary theamountof pressure exerted by the respective plunger-s, therebyincreasing the field of application of the instrument.

I attain the production of an instrument having the above-mentionedcapabilities and features by means of the structure illustrated in theaccompanying drawing, in which- Fig. l is a view of the front of theinstrument;

Fig. 2 is a section on line 2-2'of Fig. le; and,

Fig. 3 is ayfragmentary enlarged detail of the differential indicatingarrangements.

I have employed like reference characters to indicate similar parts in,the several figures.

The frame of the instrument is an elongated element of H section, uponone side of the web, 5, of which the instrumentahties are mounted, theflanges, 6, being so proportioned as to extend equally in oppositedirections from the plane of the plungers, 7 and 8. Upon the instrumentside of the web, 5, between and at opposite ends of the flanges, 6, aresecured blocks, 9 and 10, in each of which blocks are three aligningbores, 11, 12 and 13. Fitting and fixedly secured in the central bores,12, is a rod, 14, which extends beyond the block, 9, at one end of theinstrument and upon this ex` tended end is provided a knob, or handle.15, by means of which the instrument can be pressed in the desiredldirection with the de-v sired amount of force. Extending through andbetween the aligning apertures, or bores, 11 and 13, are ythe plungerrods, 7 andV 8. These plunger rods move longitudinally in theirrespective bores and upon their ends opposite .the location of the knob,15, are provided` with feet, 18, which may be shod with leather, 19, orany other desired, and suitable material to lessen the liability of theslipping of these respective feet. Blocks, 2O and 21,.are fixedlysecured to the respective plunger rods, 7 and 8, intermediate the endblocks, 9 and 10. and these intermediate blocks, 2O and 2l, arerespectively secured to the end block, 10, by `means of any sujtal'ilestress indicating means, such, for instance, as the spring balances, orscales, 22 and 23.

To a lateral embossment 2()n of the inter mediate block, 20, issecuredthe fixed point, 24,v of any suitable spring actuated microineterdevice, 25, such, forrinstance, as a lens measure having, preferably, ascale, 25, and an indicator hand, 25D, co-operating with said scale. Themovable member, 26, of Athe micrometer device 25, engages with thelateral extension 21"L of movable block, 21.

The spring actuated micrometer device, or lens measure, referred toabove, is exemplified by the ordinary lens measure used by dealers inspectacles and veyeglasses for a. considerable time. hishdevice consistsusually of a disked shaped casing`27 having a rectangular extension 28at one` side thereof. A movable pin'26, heretofore referred to, extendsthrough the center of the extension 28 and radially with the diskedshaped casing. This movable 'pin 26 Iis pressed outwardly to the fullextent of its movement by a spring and the movable pin 26 is associatedwith the pivot carrying the indicator arm 251. through theinstrumentality of a series of compound levers whereby the slightmovement of the pin 26 causes a relatively large movement of theindicator arm or pointer 25". In the usual lens measure two fixed pinsproject from the extension 28 on either side of the central pin and inCalibrating the dial 25, over which the indicator arm or pointerrotates, Va zero lli) mark is placed at the point occupied by theindicator arm or pointer when the movable pin 26 is forced back into theplane occue pied by the ends of the two fixed pins. i

It will be seen from the foregoing that when the movable pin isprojected from the mechanism beyond the plane of the ends of the twofixed pins, the indicator' arm will be at some position upon one side ofthe zero mark on the scale, and when the mov-V able pin is forcedfurther in than the plane of the ends of the two fixed pins, theindicator arm will be at some point upon the opposite side of the zeromark upon the scale.

In adapting this lens measure to the present instrument but one fixedpin is required. This fixed pin 24: is secured to block 2O by boring thelateral and upwardly extending embossment 20L thereofand forcing pin 24:into said bore to such a distance that when the main faces of blockvZOcarried by rod 7 and block 2l carried by rod 8 are aligning theindicator arm or pointer 25h will be Yabove the zero mark upon the discor scale, so that if rod 7 is forced back further than rod 8 theindicator will swing to one side of the Zero mark, and if rod 8 isforced back further than rod 7 the indicator arm will swing to theopposite side of the zero mark.

It will be seen from the foregoing description, taken in connection withthe drawing", that when the instrument is placed with the feet, 18, uponthe tissue groups, the action whereof is to be examined and compared,and pressure is applied through the knob, or handle, l5, the amount ofstress exerted upon each tissue group will be indicated by the scales,22 and 23, and, also, at

the same time, any differences of resistanceV to the action of theplungers will be directly shown by the micrometer indicator hand, 25h. i

Having described my invention, what I claim is new, and desire to secureby Letters Patent, is-

l.. An instrument for measuring ditlerew tial of resistance to appliedpressure, comprising a frame to which force is applied, a plurality ofindependently movable plungers carried by said frame, separate meansextending between the frame and the respective plungers for indicatingthe pressure applied to the subject matter under test through theseveral plungers, and independ- 1,e19,491 i i ent means for showing thedifferential bei'- tween the action of the several plungers.

2. An instrument for measuring differential of resistancel to appliedpressure, comprising a frame a plurality of independently movableplungers. mounted in said frame, means for yieldingly maintaining saidplungers in "a uniform relation to said frame and independent means for'showing the dif-` ferential between the action of the several plungers.i *Y j 3. An instrument for measuring dili'er# ential of resistance toapplied pressure comprising a body, a plurality of plungers forengagement withthe subject matter under test, said plungers extendingfrom said body and having independent reciprocable rela`` tion to saidbody, means for maintaining saidl respective plungers yieldingly inpredetermined relation to said body, anindicz tor carried by one of saidplungers and means carried by the other of said plungers extending intoco-active relation with said indicator for showing relative movementbeltween said plungers.

4l. An instrument for measuring difierential of resistance to appliedpressure com-V prising a body, a plurality of plungers for engagementwith the subject matter under test, said plungers extending from saidbody and having independent recipro'cable relation to said body,independent means for maintaining said respective plungers yieldingly inpredetermined relation to said body, an indicator carried by one of saidplungersand means carried by the other of said plungers extending intocov-'active relation with said indicator for showingrelative movementbetween said plungers..

5. An instrument for measuring differential of resistance to appliedpressure comprising a body, a plurality of plungers for s 1 Vengagementwith the subject matter under test, said plungers extending from saidbody and having independel'lt reciprocable relation to said body, springscale devices for maintaining said respectivel pluugers yieldingly inpredetermined relation to Y said body, au Vindicator carried by one ofsaid plungers and means carried by the other of said plungersextendinginto co-active relation with said indiciato'rfor showingrelative movement between said plungers.

